I infer from this that Tepco has mountains of video that might be in the public interest, so far unseen by the public. It seems they might film "anything and everything" that happens.

I'm intrigued that this particular clip ends immediately after the incident. Consequences, if any, are not visible.

I got the sense that they activated the electromagnet and that the beam "jumped" to the left of the image, but that the force was not strong enough to hold it. As these things go, it's probably better than if the beam got dropped from a great height, but of course anything might have happened.

I watched the vid again, prompted by a comment downthread by ForwardAssist and – wow – the details looked quite different on followup.

This time it seemed to me that the right-side finger of the grapple stood the beam up, getting ready to close the fingers, and the beam slid off whatever had been supporting it just under the water, allowing it to slide vertically into deeper water. The sudden slide is what I thought earlier was an electromagnetic "pull".

I knew something about the unreliability of eyewitness reports, but I just saw a video that looked totally different the second time through. Very humbling!

If you want to test your own observational skill, here's one way to do it (posted elsewhere earlier):

That's it?? Some of that scrap is going to get banged around the fuel assemblies no matter HOW careful they are – its demolition work.

How bad could they really ding anything worse in the SPF than it is right now? Tons of concrete and mangled steel from the roof crashed into the pool *after* the RPV (right next to it) exploded. If there was anything 'bad' about dropping that beam, then TEPCO would have never released the video.

If the contents of the sfp3 melted and formed a critical mass of Pu239, the result would be a nuclear explosion that would be able to blast the whole mess to kingdom come. This can't be sfp3. Perhaps they made a mistake and meant to say sfp4. We saw the 100 ton crane assembly flying like a rocket ship 1000 feet in the air.

What if it wasn't a mistake at all? A worker at Fukushima has to know now that they will never survive.

Start watching for acts of deliberate sabotage now. Or mental-illness induced Kamikaze delusions. If there are any psychiatrists in Japan treating these workers they need to break confidentiality rules for public safety reasons immediately.

These cranes are guided remotely. Not easy to do, especially with all the debris. I doubt very much that this was done deliberately.

The real damage was done when the nuclear power plant was built to begin with. This is true of every nuclear power plant and reactor in the world. This technology is not safe under any circumstances and is extraordinarily expensive and the costs are exponentially rising every day.

Every plant must be shut down immediately and no new ones built. The planet cannot sustain the cost in lives or in dollars.

Spontaneous chain reactions, releasing a flash of aurora-blue light and a surge of neutron radiation with the gamma rays emitted is called criticality. Let's say Pu-242 releases 1.65E06 neutrons per second for 1 metric ton fuel and neutrons will be thermalized and about 3 neutrons are produced per fission making the total neutron production rate 6.56E8 neutrons/sec for 1 metric ton. However, the full mass of fuel in the core is 69 metric tons. Therefore, the source strength of the core due to spontaneous fission is 4.53E10 neutrons/sec.http://lewis.armscontrolwonk.com/files/2011/03/Cause_of_the_high_Cl38_Radioactivity.pdf
From the first drop to the last drop of molten fuel you have surges with the above calculations being a touch in the dark due to little distinguishes made between solid and molten and the exact composition unknown at the time. These surges cause criticality and criticality causes surges. Some of these become slow neutrons and end up in another nuclide. Therefore: Fission is minimized by the amount of natural fusion occurring. The gross imbalance between neutron donation and neutron acceptance causes a surge. When a new rod falls onto the blob there will be a surge! Which one is fact, which one is myth?http://science.time.com/2011/03/30/has-fukushimas-reactor-no-1-gone-critical/
?

majia, Oom: "technogenic disaster". Nice turn of phrase. It becomes obvious from the Fukushima experience that nuclear reactors have a very bad failure mode. Much more work must be done to anticipate the behavior of Rogue Nuclear Reactors, that is, corium acting in bedrock and groundwater. Rogue Nuclear Reactors operate without RPV, control rods, fuel assemblies, control rooms, human operators, containments, secondary containments, or moderators. It's going to take a lot of effort over the next 2 of 3 hundred thousand years or so to control the 3 Fuku Rogue Nuclear Reactors, plus other accidents that may occue from time to time until our aging nuclear plants have all been successfully decommissioned.

If i remember correctly, the webcam-footage from the incident show the beam falling some distance before hitting the pool.

To me, it looks like this beam is lodged right in or just above the surface of the water. Notice the water surface moving right before the beam falls, while the crane is trying to manipulate it. And it breaks waves immediately after or even during the fall.

Also, wasn't it the rear end of a crane that did it in the webcam-footage?

They were in the process of trying to remove this one and it looks like it 'slipped through their fingers'!

Propagandists took control of the entire complex and all the video and news releases within a couple weeks of the disaster. The reason it wasn't sooner than that is because of all the chaos from the explosions and tsunami aftermath. Furthermore, there was a true desire by the Japanese to share in their misery and ask for help in the early days. If this wasn't the case, we never would have seen the video clips of exploding reactors. Fact, cooling was lost to three active (but scrammed) cores, and circulating coolant was lost to seven pools. Ocean water was used as coolant for many days to prevent further catastrophies. Salt cacoons formed around fuel causing increases in temperature and decomposition. Images and analysis cannot be trusted due to the classified nature of this disaster.

While it is possible that something more may have happened, forget about it. This is just a baby step as far as cleanup and demolition is concerned. If we are to worry about everything and anything that is dropped, then we have TOO MUCH to worry about. If you think this is a major snag in cleanup, then you worry too much.

Reminds me of those coin operated games where there is a box filled with stuffed animals and you try and grab one by working a crane, lining it up, then pushing a button to drop the claw into the toys to grab one. 9 out of 10 times they never work. Usually the claw is weakly calibrated and the toys are packed too tightly. Maybe they need to hire a carnival worker to get this to work. What a mess!

That stirred a memory, enoughalready45. When I was about 12 years old I was trying to get goodies out of one of those machines at the CNE fair in Toronto. Some stranger kids gathered around. I was flattered, thinking they were admiring my skill. After a while I discovered they were picking my pockets while I concentrated on the crane!

Huh? I don't get it. In fact, when I see the pile of debris already in the pool, this one dropped piece of steel is laughable. "Oh dear! We have bumped a little piece of steel into this SFP which is already half full of big chunks of steel and concrete debris that were deposited there by a "small" nuclear explosion. We are very concerned."

Not to belabor the point, but the implement in that video is a grapple, not a magnet. The jaws must close and grip the load, there is no magnetic field. Comparison to an arcade skill machine is somewhat valid. That particular grapple is self contained, controlled by it's own radio remote pendent, opens and closes hydraulically, is powered by a small diesel engine on board the grapple itself, and carries it's own fuel. It requires no connection to, or interaction with the crane. As far as the crane is concerned, it's just another load hanging from the hook.

As stated previously, the cranes are being operated remotely from a bunker. Depth perception is tricky in those conditions. Also, that crane must have 200ft or more of boom. Imagine playing the arcade skill game, but this time your claw is hanging from 200 feet of cable. With that length of boom, and that much cable deployed, with a relatively light implement on the hook, you can move the boom head 2 feet before the load shows even the slightest signs of inclination or movement. It takes an exceptionally fine touch and deadpan consistency.

The object was clearly brushed into the pool by slight contact, and I estimate that it fell between 5 to 7 feet. Weighing half a ton, I'd say it generated approximately 10 tons of force. Looks like it landed solidly, so I'm betting it hit the concrete floor, not a readily crushable object.

Thanks, ForwardAssist. You sound like you know the territory – and I certainly don't. My electromagnet comment was based on someone's earlier post and on what I thought I saw in the vid. Grapple it is, then.

Would there be two remote operators (one each for crane and grapple, perhaps a third running the camera) or does one person do it all?

Typically they are simple devices, battery powered, light, hand held, and can be held in one hand, placed on a flat surface, or hard mounted. Typically they have an emergency stop or "E-Stop" button, an open button, and a close button.

I'm not certain how Kajima has their control system networked, because I doubt you could maintain direct radio contact from inside the bunker they are operating from. They'd have to relay the signals somehow. But that's a technical rambling…..

Thanks for the description of the grapple. I figured it had to be self-contained, since no control signals cable can be seen.
I also agree the dropping of the beam into the pool was both an easy mistake, and one of little consequence. In that area you can see the rubble is heaped in the pool right up to the edge of the pool. The beam probably never touched a fuel rod, since in most of the pool those are probably under meters of rubble already. TEPCO just released a SFP3 video showing some fuel bundle handles sticking up out of light rubble, but I bet that's just some relatively clear section of the pool.

Another point is that comparing recent pictures to pictures of this area soon after the accident, TEPCO has already removed a great deal of heaped-up rubble. That beam was probably pinned down by stuff lying on top of it, and became unstable as junk above was removed. A difficult thing to judge, via a single distant crane-mounted camera.

Despite my loathing for the TEPCO management, I have the greatest respect for the workers on site. Just being in the area is a virtual death sentence (in terms of greatly reduced life expectancy) and I'm sure most of them know it.

This video shows footage of the debris removal technique. One crane is employing a grapple to hold a section of superstructure, and another crane is employing a demolition shear to cut the section free from the standing debris pile.

Nothing is dropped in this particular footage. I suspect it was shot before the footage of the beam being knocked into the pool.

It's hard to tell from this footage, but the shear might not be suspended from a crane, it potentially could attached to an excavator located on the improvised decking built alongside the refueling level's outside perimeter.

It's just unbelievable that the LUNATICS of this bloody Japanese electrical-utility are playing just like infants with the lives of a whole planet.
They are the utmost example of INCOMPETENCE like people who don't know what are they dealing with, and they suddenly find themselves with a situation that's TOTALLY OUT OF CONTROL for their *diocy.

I mentioned elsewhere, just shooting ideas at the wall, maybe they should freeze the pool. A foot of ice can hold the weight of a pickup truck.

2 or 3 feet of ice on the surface of the pool would still cool the pool, support the debris pile, arrest falling objects, or at least disperse some of their kinetic energy. They could thaw specific areas of the surface, or cut and remove sections to provide access.

Interesting idea. But considering the pros and cons, it's probably not worth the trouble – or even possible.
Very difficult to rig the amount of cooling systems required close by, especially given that the fuel rods are a large source of heat still.
Hardly worth it, since most of the rod assemblies are likely already under thick heaps of rubble, and more won't matter.
But most significantly, it might be risking causing (or worsening) cracks in the concrete walls of the pool. Water expands when changing state to ice, remember. Freezing water can split rocks… and concrete too.

I don't think that is careless work by the crane operator, instead it is just inevitable that there will be unforeseen problems dealing with the ruins of the buildings. As long as the dropped objects don't puncture the steel pool liner it really won't matter…from the views of the wreckage already in the pond there is no way they will ever be able to empty the pool for decades. Earthquakes loom large in the battle to save Japan.

They are going to need a different plan for containment and I don't think they have any viable plans at present. They need scientists from around the world to analyze the options. Tepco has none.

SUBMIT YOUR NEWS TIPS

Your identity will not be made public unless you request it

LIVE FEEDS

Receive Occasional Enenews Newsletters

sending...

Name

E-mail

SUPPORT ENENews

ENENews receives no funding from anyone or anything, except 1) People who donate via the button below, and 2) Google, who pays for the two ad spots. Thanks to all who have donated or are planning on doing so, it's nice to know people appreciate your work.